CYTOCHEMICAL DETECTION OF ENDOGENOUS PEROXIDASE IN THE ACINAR-CELLS OF THE HAMSTER SUBMANDIBULAR-GLAND

The presence of endogenous peroxidase activity in the hamster submandi bular gland was investigated cytochemically by light and electron micr oscopy using diaminobenzidine methods. After fixation of tissue with 2 % paraformaldehyde-2.5% glutaraldehyde and incubation in a DAB reactio n medium containing 0.01% H2O2, the peroxidase reaction product was lo calized in the nuclear envelope, the cisternae of the endoplasmic reti culum, secretory granules and the Golgi apparatus in both the acinar a nd granular duct cells of the submandibular gland. This is in contrast to earlier investigators who failed to detect peroxidase activity in acinar cells of the hamster submandibular gland and reported that pero xidase is localized only in the granular duct cells. The discrepancy m ay be caused by differences in experimental procedures. It is suggeste d that fixation of tissue with a high concentration of glutaraldehyde and incubation in a DAB reaction medium containing a high concentratio n of H2O2 inhibits the peroxidase activity of acinar cells in the hams ter submandibular gland.